Like the late Ansel Adams, photographer Sebastiao Salgado has an immediately recognizable visual style.

In more than 40 years of shooting (he didn’t pick up a camera until he was in his 20s) the Brazilian-born Salgado mostly has photographed other human beings struggling to survive.

His work has taken him from huge gold mining pits in South America (where 60,000 laborers manually lug bags of dirt up treacherous ladders — looking like insects swarming over an anthill) to refugee camps in Africa and a still-primitive tribe in the jungles of New Guinea.

Photo from Salgado’s series “The Miners of Serra Pelada”

His work, invariably in black and white, is unsettling. For while his politically-charged subject matter is often disturbing (the corpses of African children dead of starvation, the Rwandan genocide, civil war in the former Yugoslavia), his artistry is overwhelming.

Shooting rapidly using natural lighting, he instinctively finds the right angle, the right composition, the right moment to push his shutter button. He discovers beauty in ugliness. (Though it’s not mentioned in this doc, some critics have accused Salgado of prettifying human misery for Western bourgeoise consumption.)

“The Salt of the Earth,” an Oscar nominee this year for best documentary feature, follows Salgado’s career through his photographs and his personal commentary.

Directed by the great Wim Wenders and Salgado’s son, Juliano Ribeiro Salgado, the film is an overwhelming sensory experience even as it tugs at our political consciousness.